Those seals can be seated improperly (has happened to me), reseat them and you are OK.

ALSO:
It can be that the seals are dried out due to UV exposure (keep Roadsters in the garage, not outdoors, do not buy a roadster that has been sitting outdoors, as new parts are no longer available.)
It can be that the window's travel adjustment is off, the service manual details how to adjust how far UP the window goes.